1. Field of Industrial Applications
The present invention relates to a cleaner for a conveyor belt by which the leavings of conveying material, e.g. coke, stuck on the surface of a conveyor belt are removed during the return movement of the belt.
2. Description of the Related Art
A prior art cleaner for a conveyor belt is disclosed in U.S. Pat. No. 3,841,470 wherein the conveyor belt includes a plurality of cleaner means disposed thereon in the transverse direction of the conveyor belt at the return side of the same. Each cleaner means has a scraping portion thereof which intends to come in contact with the belt surface, while all of which are arranged in linear relationship. More specifically, a scraper having, at uppermost end, a scraping portion thereof comprising of a tip member is yieldingly supported by a resilient member so that the scraping portion thereof becomes in contact with the belt surface under pressure by the resilience of the resilient member.
It is known that an endless conveyor belt, which is fitted for running in a circle between a drive pulley and an idler pulley, is supported on the forward side thereof by a plurality of guide rollers arranged at "trough" angles so as to be formed in a bow-like cross sectional shape in order to carry the transferring material in a stable manner. In other words, on the forward side of the running belt transferring the material thereon forward, the belt is supported so that the lengthwisely extending central region thereof can be arcuately deflected downward. The transferring materials are consecutively transferred generally on the central region of the belt, which will result in intensive wear on the central region of the belt surface rather than on both side regions of the same.
Because of its tendency to deflection (termed as generally a "trough" tendency), the belt is deflected upward at a point midway between the side ends thereof thus to form an arch shape in cross section on the return side of the belt where the belt runs backward opposite to the forward direction thereof after discharging the transferring material therefrom. In such an arrangement of the known cleaner, the scraping portions of the cleaner means arranged in linear relationship are prevented from meeting the belt surface when coming into close contact with the same. More specifically, there is a clearance between the scraping portions arranged linearly in said cleaner and the central region of the belt. The clearance becomes greater when the amount of wear on the central region of the belt surface is increased. Consequently, it will appear that the leavings of material on the central region of the belt surface cannot be positively scraped off by the scraping portions of the cleaner. Since the leavings of material adhered to the belt are generally greater in amount at the lengthwisely extending central region of the belt surface than the side regions of the same, some of the scraping portions disposed in the center get worn intensively in proportion to the amount of scraped material. This allows the clearance between the centrally mounted scraping portions and the belt surface to become gradually greater.
Each of the cleaner means has a scraper thereon which is supported yieldingly by the resilient member thus to be biased independently. When one of the scrappers is tilted laterally, a mass of the scraped material become trapped between the scraper and its adjacent scraper. This prevents the adjacent scraper from being biased independently, which will result in a stop of the returning movement of the scraping portion of the scraper from its biased position to its rest position for coming into contact with the belt surface.